Different Size Spare Tire

[BossEvelope]

I understand the spare tire should be the same size as the rest of my tires, but would any damage occur to the vehicle if I got a flat and had to use a different sized spare tire? I’m wondering if I run larger tires than stock which don’t fit the spare location, could I keep the spare tire the stock size? In my case I have the 20” wheels so I presume the spare would be the stock 20” as well. I wouldn’t drive for long on the mismatched spare, just enough to get home or the tire shop.

 

[EOD Guy]

IMO....... If the rear diff locker isn't turned on, it'll work. I think you will get error lights on the dash tho'. I would never put mismatched tires on the front. If I got a flat on the front, I'd move one of the rears to the front and place the mismatched spare tire on the rear.

Just some thoughts........ On my Taco, I was able to get the larger spare to nest in the stock location by cutting (metal cut off wheel) one of the centering points off the frame. This allowed about 2 inches of adjustment, it's a jiggle fest to get the larger spare to nest, but after 29k miles, it's exactly where I put it, no issues at all.

My 2nd thought..... depending on how much bigger you are going, it might fit if it's deflated to 2-3 lbs of air. Once you get the 4 mounted, It might be worth your time to deflate one of them and see if you can stuff it in the spare wheel space. the unmovable hard points are the trailer hitch, exhaust pipe and the rear differential. If a deflated tire fits, you would then need a portable air compressor to be carried in the vehicle.

 

[Valsmere]

For strictly emergency situations you should be ok. I completely agree with EOD Guy. Where I worked last we had a few off road beater trucks that never left the property and we threw on what ever we had available.

 

[winnrider]

So many vehicles today don't come with any spare. Instead, you get some fix a flat and a cheap air compressor. I'm certain we have all owned a vehicle with a temporary spare which is never the same size. If you live in any size city you will see nissan altimas rocking temporary spares all day long without issue. Not pretty, but serviceable.

The real question is what is your use case. Rock crawling or disappearing into the Bolivian mountains, get a fifth tire for a spare and put it somewhere. For the remaining 90 per cent of us owners, I would imagine OEM will get you where you need to go.

my 2 cents

 

[ultane]

I’ve mentioned this before, but with my 2012 Subaru Outback 3.6R, someone knifed my tire sidewall (), a Michelin Defender, IIRC, when it had ~20,000 miles on it. The Subaru shop, Costco tires, and the owners manual ALL said that I would have to replace all four tires, due to differing diameters. It was something about the all wheal driver, drive train sensors not doing well with different sized tires. I don’t know what Miss Daisy’s owners manual says about this topic.

 

[winnrider]

I’ve mentioned this before, but with my 2012 Subaru Outback 3.6R, someone knifed my tire sidewall (), a Michelin Defender, IIRC, when it had ~20,000 miles on it. The Subaru shop, Costco tires, and the owners manual ALL said that I would have to replace all four tires, due to differing diameters. It was something about the all wheal driver, drive train sensors not doing well with different sized tires. I don’t know what Miss Daisy’s owners manual says about this topic.

I guess it is manufacturer dependent and that does makes sense to replace all. I had a three Audis (2018, 2020, 2022) both SUVs and cars and replaced individual flat tires at dealer without issue. My comments were directed more to the problems that might arise due to limited, emergency type use of a smaller tire. If it's not in the Toyota manual that the same size is required (no idea) you can book it that their lawyers had to sign off on different sizes as tire upsizing (based on the comments in this forum) is common and anticipated.

Edit: p553 contains a general warning about not using any tire size other than stock, mix and match, poor tread, etc., but nothing specific to this issue so I guess it’s up to the individual owner. Some will take the chance while others won’t.

 

[BossEvelope]

Thanks for the feedback all, I think using the OEM spare to limp back home/tire shop is probably the route I’m going to take. I plan to stay in the 33-34 diameter range for the new tire setup anyway, maybe just wider than stock, so the difference shouldn’t be too big using the 20” OEM spare.

Knock on wood, I have not had to change a flat tire in like 20 years. Hope I didn’t just jinx myself here.

 

[EOD Guy]

Thanks for the feedback all, I think using the OEM spare to limp back home/tire shop is probably the route I’m going to take. I plan to stay in the 33-34 diameter range for the new tire setup anyway, maybe just wider than stock, so the difference shouldn’t be too big using the 20” OEM spare.

Knock on wood, I have not had to change a flat tire in like 20 years. Hope I didn’t just jinx myself here.

If you're staying at a 33" you probably won't be able to tell the difference when the spare is on. I've always lived by........ If I had the need for a new tire and the others had less than 1/2 of the tread left, I'd buy two and put them on the front and the best two of older three went on the rear. IMO steering tires are a lot more important than the trailing tires.

 

[ultane]

Edit: p553 contains a general warning about not using any tire size other than stock, mix and match, poor tread, etc., but nothing specific to this issue so I guess it’s up to the individual owner. Some will take the chance while others won’t.

Thank you!!!

 

[PACruiser]

So if you get the 20 inch wheel upgrade package, is the spare also replaced or is it still the factory 18s?

 

[cruisemtb]

Matching 20" spare

 

[Altitude]

When one tire is different in diameter than the others it rolls at a different rate. This can drive AWD systems crazy if they recognize that to be wheel slippage and try to reallocate torque accordingly.

As someone said, it might help to unlock the differential. And to begin with I’m not sure whether the 4WD system in these does any kind of torque vectoring. Might not be a big deal.